Research On Treatment Of Printing And Dyeing Wastewater With High Concentration By Micro-electrolysis

Printing and dyeing wastewater is a big one in our country industrial wastewater. It's characteristics include difficulty to remove color , high organic concentration, complex constituent and hard to treat with bio-treatment. Because the wastewater is mainly polluted by the organic matter, the most popular treatment way is bio-treatment. The printing and dyeing plants wastewater treatment process is physical chemistry-biologic chemistry. The process removes the most color and some organic contamination by physical chemistry way (heading off by bar, using flocculants and electrolysis air flotation), then treats by biology to make the effluent meets the release standard. The process isn't a ideal one because of its high cost and long process, so it's important to research a new way to treat the wastewater.The paper summarizes the sources of printing and dyeing wastewater, the water's qualities characteristics and the popular treatment process. The main clusions are as below:(1) Research on the most influence factors shows the optimum conditions are: pH value was 5, air volume of blowing was 0.4 L/ min, the weight ratio of iron to carbon was 2 : 1, and reaction time was 60 min.(2) Researching the principle of micro electrolysis degraded the wastewater. From the research we know the principle involves oxidation-reduction, flocculation, electro-enrichment, and filtration-adsorption.(3) From the experience data analysis, the equation of COD_Cr degradation with micro-electrolysis is Y=1281.57253-33.76598X+0.40631X²-0.00148X³.(4 ) It proposaled a new technological process of combining MBR(Membrane bio-reactor) named micro-electrolysis-MBR process to treat printing and dyeing wastewater. That process got an excellent achieve in the experience. After the process treatment, the average effluence water color is 5, and the COD_Cr 79.2mg/L. That accords with the wastewater release standard (I ) of printing and dyeing.